1. Field of the Invention
This invention relates to video image display apparatus, and, more particularly, to such apparatus in which the scene displayed is determined by the sensed orientation of the viewing mechanism as controlled by the user.
2. Description of the Prior Art
Prior art video display devices, such as that described in U.S. Pat. No. 3,205,303, issued Sept. 7, 1965 to W. E. Bradley, include a CRT mounted upon the helmet of the user with a combination of control equipment located separately from the CRT's. The apparatus includes a mechanical or electromagnetic device for sensing the position of the user's head, so that the scene depicted is changed dependent upon the user's head position. An image pickup device, such as a TV camera tube, is employed to pick up an image from a model scene and transmit it to the CRT mounted upon the user's helmet. U.S. Pat. No. 4,103,435, issued Aug. 1, 1978 to Herndon, discloses a head trackable wide angle system for displaying a portion of a model to the user displayed upon a screen positioned in front of the user's face. Such devices are limited in scene capability to those drawn or depicted upon a screen within the range of the pickup device, and require the user to support the CRT from his helmet.
An electronic image generation system is disclosed in U.S. Pat. No. 4,209,832, issued June 24, 1980 to Gilham et al. Gilham et al describes a fire control combat simulator in which information representing objects to be displayed is stored in a plurality of image generators. A computer composes a scene for the operator's TV monitor consisting of one or more of the objects stored in the object generators. The host computer receives analog rate signals from the operator's controls from which it determines the direction of view and displays objects from the separate object generators to be displayed on the operator's TV monitor. Such systems are limited to those applications in which a TV monitor is an adequate display.